1. Field of the Invention
The present invention relates to a device for storing information, in particular information formed by digital data, in a transmission system between at least first and second terminals coupled together by one or more optical fibers forming a connecting channel.
2. Description of the Prior Art
For different reasons and particularly in the case of momentary occupation of the connecting channels, it is necessary to have storage means.
Therefore, memories are usually associated with the terminals connected to a connecting channel which may have diverse logic architectures. The functions fulfilled may also be diverse.
Memories of the buffer type are generally associated with the terminals capable of storing, at least temporarily, one or more messages to be transmitted or received.
It is known moreover that an optical fiber behaves, with respect to a guided wave, as a delay line.
In fact, since the speed of propagation of light is finite, a light pulse injected at one end of an optical fiber propagates there along in a guided mode and reaches the other end after a time interval which will be called in what follows "mean propagation time .tau..sub.o ", which time may be easily determined if the length of the optical fiber is known. Thus, an optical fiber may be used as delay line and therefore as storage element of a memory of the data flow type; the storage capacity of the memory of this type depending on the propagation time, i.e. in the present case on the length of the optical fiber and on the flow rate of the information injected at the input.
The invention takes advantage of the physical phenomenon which has just been recalled.